On August 12, Google announced their Panda algo rolled out for Korean, Chinese and Japanese. Thus, Panda went global.

And now we have Panda 2.4 update.

Here's a snippet of the changes in Panda straight from the announcement blog post:

Quote:

Whatís changing?

Currently, Google Analytics ends a session when:

* More than 30 minutes have elapsed between pageviews for a single visitor.
* At the end of a day.
* When a visitor closes their browser.

If any of these events occur, then the next pageview from the visitor will start a new session.

In the new model, Google Analytics will end a session when:

* More than 30 minutes have elapsed between pageviews for a single visitor.
* At the end of a day.
* When any traffic source value for the user changes. Traffic source information includes: utm_source, utm_medium, utm_term, utm_content, utm_id, utm_campaign, and gelid.

With both Panda algo and Pandalytics updated right on the same day, it has become confoundedly difficult to make sense of the data for webmasters. On top of it, Google acknowledged a bug in the initial release.

Quote:

We identified an issue responsible for unexpected traffic changes following our recent update to how sessions are defined in Google Analytics. A fix was released at 2pm PST Tuesday August 16th. The issue affected some sites using the following configurations:

1. If a user comes to a customerís site with a space in some part of their traffic source data, then revisit the same landing page during that session by refreshing the page or later pressing the back button, a new session will be created for every hit to that page. (Clicking a link elsewhere on the site that leads back to the page should not matter.)
2. Google Analytics implementations using multiple trackers (an unsupported configuration) are also affected when a space is included in the traffic source data. These sites will see fewer visits from new visitors, and more visits from returning visitors (with some variation due to different implementations).

Webmasters need a few days of observing to see whether their rankings change and/or stabilize.